Saccharomyces boulardii
Best-in-class: Sacro-B
A beneficial probiotic YEAST (not a bacterium) that is uniquely resistant to antibiotics — making it ideal support during and after antibiotic courses.
How Saccharomyces boulardii actually works
A yeast rather than a bacterium, which is the defining property: antibacterial antibiotics do not kill it, so it can run concurrently with a course rather than after it. It works by competitively excluding pathogens, degrading bacterial toxins directly, and stimulating secretory IgA.
Saccharomyces boulardii quick facts
| Suggested dose | One serving daily, especially during/after antibiotics or travel. |
| How often | Daily, especially during antibiotics |
| Who it's for | Anyone on antibiotics, traveling, or with acute gut disruption. |
✅ Clinically validated
- Strong RCT/meta-analysis support for preventing antibiotic-associated and traveler's diarrhea.
- Because it's a yeast, antibiotics don't kill it — it works alongside them.
📊 Correlative data
- Antibiotic use and travel track with gut disruption that S. boulardii mitigates.
🧪 Theoretical / extrapolated benefits
- Anti-inflammatory and pathogen-crowding mechanisms are well-characterized for this strain.
These tiers tell you how much human evidence exists — not how well something works. This is the research space, and most of what’s in here is new rather than disproven. Something sitting at “theoretical” usually means nobody has funded the trial, not that the trial was run and failed.
The trap runs the other way too: something can be clinically validated and still do very little for you specifically. A statistically significant result in a study population is not a promise about your body.
- ✅ Clinically validated — human randomised trials or meta-analyses support it. The strongest footing available.
- 📊 Correlative — observational or epidemiological data. Suggestive, and genuinely useful for direction, but it cannot establish cause.
- 🧪 Theoretical / mechanistic — the mechanism is understood and often demonstrated in cells or animals, and the human trial doesn’t exist yet. Unproven is not the same as ineffective. Plenty of what’s standard practice today sat here five years ago.
✗ is a safety flag, not a grade. Where you see it, the concern is harm — not a disappointing trial. A compound tested for one purpose and found not to help there can still be worth studying somewhere else, so a negative result never gets rendered as a cross. It sits alongside the tier, because something can be both well-studied and genuinely risky.
My job is to tell you which one you’re looking at, and let you make the call. Grading something low isn’t me dismissing it — it’s me refusing to oversell it. This is the research space, and being able to reason forward from a mechanism matters as much as waiting for the trial.
Strong meta-analysis support for antibiotic-associated diarrhoea and for Clostridioides difficile, which is more robust evidence than most probiotics have. The antibiotic-compatibility is genuinely useful and under-exploited. The real caution: it should not be used in anyone significantly immunocompromised or with a central line, where fungaemia has been documented.
Saccharomyces boulardii — safety & side effects
- Gas, bloating and constipation.
- It is a yeast, and fungaemia has been reported in critically ill patients and those with central lines — the same contraindication as bacterial probiotics, with the added point that it is not killed by antibacterial antibiotics.
- Do not take with antifungal medication — it will simply be killed. Avoid with yeast allergy.
Not medical advice. If you take prescription medication or have a diagnosed condition, check this against it with a pharmacist or doctor — pharmacists are underused and free.
Where to get Saccharomyces boulardii
Buy Sacro-B at Thorne →Get the complete breakdown for Saccharomyces boulardii — inside the Academy alongside the full interactive Vault.
Unlock in the Academy — $10/mo →- When to take it, and what to take it with
- Which form actually absorbs
- Who it's worth it for
- Best-in-class brand pick
- Coach Cam's stacks and notes
Get the complete breakdown for Saccharomyces boulardii — inside the Academy alongside the full interactive Vault.
Unlock in the Academy — $10/mo →Bloodwork to run alongside Saccharomyces boulardii
Run these before you start, and again after 8–12 weeks. A baseline you didn’t take is one you can never go back for.
| Marker | What it’s watching for |
|---|---|
| Complete Blood Count (CBC) with Differential | Anaemia is the commonest sign of a gut absorbing badly |
| Ferritin | Iron is the first thing malabsorption takes |
| Vitamin B12 | The second thing, and the one with permanent consequences |
| hs-CRP (High-Sensitivity C-Reactive Protein) | Separates inflammatory bowel disease from IBS |
The Gut Health & Absorption panel covers these in one order — 11 markers, $208.80 with the discount applied.
Check results you already have → · All 102 markers A–Z
Saccharomyces boulardii — frequently asked questions
What is Saccharomyces boulardii?
A beneficial probiotic YEAST (not a bacterium) that is uniquely resistant to antibiotics — making it ideal support during and after antibiotic courses.
What is the suggested dose of Saccharomyces boulardii?
One serving daily, especially during/after antibiotics or travel. This is a general reference for education only — statements have not been evaluated by the FDA and this is not medical advice.
Where can I find Saccharomyces boulardii dosing and the full breakdown?
The suggested dose and the full evidence — clinical, correlative and theoretical — are on this page. What's inside the Academy is when to take it, which form actually absorbs, the brand worth buying and Coach Cam's stacks.
Where can I buy Saccharomyces boulardii?
Coach Cam sources Saccharomyces boulardii from Thorne, with 10% off auto-applied at checkout — use the buy link on this page.
Build your foundation with Coach Cam
The full Supplement Vault — 350 products across 14 categories with clinical, correlative & theoretical evidence, plus my Thorne partner links — lives inside the Academy alongside 237 peptides.
Join the Academy — $10/mo →What Saccharomyces boulardii is used for
Saccharomyces boulardii appears under 2 goals in the Vault’s goal router, grouped by the mechanism it works through rather than by how much trial evidence exists. Each link opens that pathway in full, with the alternatives beside it and the bloodwork that tests it.